This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A155668 #13 Jan 12 2019 19:25:06
%S A155668 1,4,58,820,10546,128284,1509418,17390020,197581666,2223729964,
%T A155668 24863682778,276721736020,3069708899986,33972956330044,
%U A155668 375351787072138,4142063797326820,45668254886861506,503195228685608524
%N A155668 11^n-8^n+1.
%H A155668 <a href="/index/Rec">Index entries for linear recurrences with constant coefficients</a>, signature (20,-107,88).
%F A155668 G.f.: 1/(1-11*x)-1/(1-8*x)+1/(1-x). E.g.f.: e^(11*x)-e^(8*x)+e^x.
%F A155668 a(n)=19*a(n-1)-88*a(n-2)+70 with a(0)=1, a(1)=4 - _Vincenzo Librandi_, Jul 21 2010
%t A155668 Table[11^n-8^n+1,{n,0,20}] (* or *) LinearRecurrence[{20,-107,88},{1,4,58},20] (* _Harvey P. Dale_, Jan 12 2019 *)
%o A155668 (PARI) a(n)=11^n-8^n+1 \\ _Charles R Greathouse IV_, Jun 11 2015
%Y A155668 Cf. A155646, A155647, A155648, A155649, A155650, A155651, A155652, A155653, A155654, A155655, A155656, A155657, A155658, A155659, A155660, A155661, A155662, A155663, A155664, A155665, A155666, A155667.
%K A155668 nonn,easy
%O A155668 0,2
%A A155668 _Mohammad K. Azarian_, Jan 31 2009